Employers have long preferred to manage without the incursion of a trade union in company affairs. Much of the extant literature views managerial opposition to unions in terms of discrete typologies of union suppression and/or substitution. In this paper we present a conceptual analysis that questions the efficacy of such approaches. Given the limitations identified, the paper argues that managerial ideology provides a deeper theoretical and historically grounded form of analysis to explain hostility towards collective forms of worker representation. The paper explores the antecedents of managerial ideology and the logic to how and why trade unions are opposed. It concludes that as ideology drives managerial decollectivising strategies, lessons can be learnt for future union organising